run over without difficulty almost the entire circle of the natural philosophy; those, on the other hand, who are not yet arrived at perfection, and who have not been able to hear me lecture on these subjects, will be able in their minds to run over the main of the essential notions, and to derive assistance from them for the tranquillity and happiness of life.”
This then is his letter on physics.
XXV. About the heavenly bodies he writes thus:—
EPICURUS TO PYTHOCLES, WISHING HE MAY DO WELL.
“Cleon has brought me your letter, in which you continue to evince towards me an affection worthy of the friendship which I have for you. You devote all your care, you tell me, to engraving in your memory those ideas which contribute to the happiness of life; and you entreat me at the same time to send you a simple abridgment and abstract of my ideas on the heavenly phænomena, in order that you may without difficulty preserve the recollection of them. For, say you, what I have written on